Global instance of class - iphone

Question

Im trying to make an instance of a class available in all methods in the .m file. Instead of doing this inside every method:
-(void)viewDidLoad
{
Class *c = [Class new];
}
My attempt in the .h file:
#interface RandomViewController : UIViewController
{
Class *c [Class new];
}
But It does'nt work, I get error
Expected ';' at end of declaration list
How would I make this possible?
Thanks

Answer 1

Create an instance variable, and set it up in your designated initializer. Here's a sample #implementation block.
#implementation RandomViewController {
// Instance variable names should start with an underscore, by convention.
Class *_c;
}
...
// Designated initializer for UIViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
_c = [[Class alloc] init];
}
return self;
}
...
- (void)someMethodThatNeedsAClassInstance
{
[_c doSomething];
}
If you're not using ARC, you'll need to add [_c release] to your dealloc implementation.
Now, in every method in your class, you may refer to _c and get the instance you created in the initializer. As a side note, this isn't really a 'global' instance - it is per-object. Each individual view controller you create will have its own instance of _c. Also, an even better approach is to declare a property and not bother declaring an instance variable at all.

Answer 2

In .h file:
#interface RandomViewController : UIViewController
{
Class *c;
}
In .m file:
-(void)viewDidLoad
{
c = [[Class alloc] init];
}

Answer 3

what do it do the class method? if return void:
Class.h file:
#interface Class: NSObject
{
}
- (void)new;
RandomViewController.h
#interface RandomViewController : UIViewController
{
Class *c;
}
RandomViewController.m file
-(void)viewDidLoad
{
c = [[Class alloc] init];
//call the method
[c new];
}